*{margin: 0;padding: 0;}
.nav-top{
    background-color: #fff;
    position: relative;
    height: 50px;
}
.nav-left{
    position: absolute;
    height: 50px;
    left: 0;
    top: 0;
}
.nav-right{
    position: absolute;
    width: 200px;
    height: 50px;
    right: 0;
    top: 0;
}
.nav-lbottom{
    position: absolute;
    height: 50px;
    left: 0;
    bottom: 0;
}
.nav-rbottom{
    position: absolute;
    height: 50px;
    right: 0;
    bottom: 0;
}
ul{
    list-style: none;
    overflow: hidden;
    line-height: 50px;
}
li{
    float: left;
    margin-left: 30px;
    font-size: 13px;

}
li:hover{
    color:blue;
    cursor: pointer;
}
.a{
    color: gray;
    font-size: 10px;
    width: 85px;
}
.a:hover{
    color:black;
    cursor: pointer;
}
.b{
    color:gray;
    font-size: 1px;
    width: 130px;
}
.denglu{
    color:white;
    background-color:rgb(66, 66, 177);
    border-radius: 20px;
    border: 1px solid #333;
}
button{
    width: 90px;
    height: 46px;
    text-indent: 15px;
    background-position-y: center;
    position: absolute;
    right: 0;
    top: 0;
    border: none;
    outline: none;
}
.search{
    position: relative;
    width: 650px;
    height: 46px;
    border: 1px solid rgb(12, 25, 97);
    border-radius: 15px;
    overflow: hidden;
}
input{
    width: 560px;
    background: url("../images/xiangji.jpg") no-repeat;
    background-size: 46px;
    background-position-x:510px;
    position: absolute;
    left: 0;
    right: 0;
    border: none;
    outline: none;
    height: 46px;
}
button{
    background-color:rgb(65, 65, 226);
    color:white;
    position: absolute;
    right: 0;
    top: 0;
}
.content{
    width: 680px;
    height: 600px;           
}
.center{
    margin-left: auto;
    margin-right: auto; 
}
img{
    margin-top: 40px;
    height: 120px;
}
.ting{
    text-align: center;
}
.btn{
    margin-top: 50px;
}       
.content-list{
    overflow: hidden;
}
.content-list>div{
    width: 50%;
    float:left;
}
